Abstract
Purpose :
To objectively quantify change in papilledema after optic nerve sheath fenestration (ONSF) using optical coherence tomography (OCT) in Idiopathic intracranial hypertension (IIH).
Methods :
Twenty-four eyes of 12 subjects diagnosed with IIH were prospectively enrolled to investigate changes in nerve head morphology using OCT after bilateral ONSF. The central line of HD 5 Line Raster exams using a Cirrus HD-OCT were acquired pre-operatively, at one day and at one month post-operatively. Papilledema height (PapH) was quantified by connecting Bruch’s membrane opening with a linear segment, and generating a normal segment from this reference line to the maximum height of the nerve head. (Figures 1 and 2) The x and y dimensions of the height segment were scaled and converted to mm based on scan parameters. Images of poor quality were excluded. Paired T-tests were performed between pre-op and 1 day post-op, as well as between 1 day and 1 month post-op. Significance threshold was p < .05. In addition, linear regression analysis was performed between PapH and subjective estimate of papilledema graded by modified Frisén score for validation.
Results :
Three eyes of two subjects were excluded, resulting in 21 eyes of 11 subjects at one day and 16 eyes of 9 subjects at one month post-op. A significant reduction in PapH was found between pre-op (1.14 ± .37mm) and 1 day (0.92 ± .25mm; p < .001), as well as between 1 day (0.93 ± .28mm) and 1 month (0.74 ± .23mm; p < .001). A significant relationship was found between PapH and subjective estimate by modified Frisén score (R2 = .4450, p < .0001).
Conclusions :
Optic nerve sheath fenestration allows rapid resolution of papilledema in IIH subjects, with significant reduction at one day post-operatively using objective evaluation of OCT images. Future studies will involve quantification of volume of papilledema.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.